CVE-2021-28856

MEDIUMNVD 5.55.5—

5.5

In Deark before v1.5.8, a specially crafted input file can cause a division by zero in (src/fmtutil.c) because of the value of pixelsize.

CVSS v3: 5.5
EG Score: 5.5(medium)
EPSS: 41.6%
KEV: Not listed

Published

April 14, 2021

Last Modified

January 26, 2026

References (5)

cve@mitrehttps://fatihhcelik.github.io/posts/Division-By-Zero-Deark/
cve@mitrehttps://github.com/fuzzing2026/CVE-PoCs/tree/main/deark-CVE-2021-28856
cve@mitrehttps://github.com/jsummers/deark/commit/62acb7753b0e3c0d3ab3c15057b0a65222313334
af854a3a-2127-422b-91ae-364da2661108https://fatihhcelik.github.io/posts/Division-By-Zero-Deark/
af854a3a-2127-422b-91ae-364da2661108https://github.com/jsummers/deark/commit/62acb7753b0e3c0d3ab3c15057b0a65222313334

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-369Divide By Zero

Data Freshness Timeline

(refreshed 7× in last 7d / 7× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 18:16 UTCEG score recompute
2026-05-26 18:16 UTCGHSA enrichment
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-28856?

CVE-2021-28856 is a medium vulnerability published on April 14, 2021. In Deark before v1.5.8, a specially crafted input file can cause a division by zero in (src/fmtutil.c) because of the value of pixelsize.

When was CVE-2021-28856 disclosed?

CVE-2021-28856 was first published in the National Vulnerability Database on April 14, 2021, with the most recent update on January 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-28856 actively exploited?

CVE-2021-28856 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-28856?

CVE-2021-28856 has a CVSS v3 base score of 5.5 (NVD).

How do I remediate CVE-2021-28856?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-28856, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-28856

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CVE-2021-28856

📅 Published

🔄 Last Modified

🔗 References (5)